Use the graph of the function to find the approximations of the
given values.
a) 𝑓 (−1)
b) 𝑓 (0)
c) 𝑓 (1)
d)
𝑓(3)−𝑓(1)
3−1
Solutions:
This question is similar to the previous one. One difference
here is that this is a piecewise function, so we have to be aware
that a closed circle means that point is actually part of the
graph, while the open circle means that that point is not part of
the graph.
For a), go left one unit, and find that you have to go up two
units to reach the graph (the closed circle). Thus, 𝑓(−1) = 2.
For b) you just stay at the 𝑦-axis (don’t go left or right at all) and
find that you have to go down one unit to reach the graph.
Thus, 𝑓(0) = −1.
For c), go right one unit, and find that you don’t have to go up
or down at all to reach the graph (again, the closed circle).
Thus, 𝑓(1) = 0.
For d), first find 𝑓(3) (since we found 𝑓(1) already in part c).
For 𝑓(3), we go right three units and find that we have to go up
three units to reach the graph. Thus, 𝑓 (3) = 3. Then, we plug
these numbers into the given formula:
𝑓(3) − 𝑓(1) 3 − 0 3
=
=
3−1
3−1 2